Magnets, Magnetic Field, Electromagnet, Electromechanical Solenoid, Stator, Armature, DC Electric Motor and Automobile Starter Motor

Posted by PITHOCRATES - January 1st, 2014

Technology 101

(Originally published April 18th, 2012)

Electric Current flowing through a Wire can Induce Magnetic Fields Similar to those Magnets Create

We’ve all played with magnets as children.  And even as children we’ve observed things.  If you placed a bar magnet on a table and approached it with another one in your hand one of two things would happen.  As the magnets approached each other the one on the table would either move towards the other magnet.  Or away from the other magnet.  That’s because all magnets are dipoles.  That is, they have two poles.  A north pole.  And a south pole.

These poles produce a magnetic field.  Outside of the magnet this field ‘flows’ from north to south.  Inside the magnet it ‘flows’ from south to north.  So imagine this magnetic force traveling through the magnet from south to north and right out of the north pole of the magnet.  Where it then bends around and heads back to the south pole.  Something most of us saw as children.  When we placed a piece of paper with iron filings over a bar magnet.  As we placed the paper over the magnet the iron filings moved.  They formed in lines.  That followed the magnetic field created by the magnetic dipole.  You can’t see the direction of the field but it only ‘flows’ in one direction.  As noted above.  If the north pole of one magnet is placed near the south pole of another the magnetic field ‘flows’ from the north pole of one magnet to the south pole of the other magnet.  Pulling them together.  If both north poles or both south poles are placed near each other they will repulse each other.  Because the magnetic field is ‘flowing’ out from each north pole.  Or into each south pole.  The magnets repulse each other because the magnetic field is trying to flow from north to south.  If one magnet was able to rotate this repulsion would rotate the magnet about 90 degrees.  To try and align one north pole with one south pole.  As the momentum pushed the magnet past the 90 degree point the force would reverse to attraction.  Rotating the magnet about another 90 degrees.  Where it will then stop.  Having aligned a north and a south pole.

It turns out this ability to move things with magnetic fields is very useful.  Both in linear motion.  And rotational motion.  Especially after we observed we could create magnetic fields by passing an electric current through a wire.  When you do a magnetic field circles the wire.  To determine which direction you simply use the right-hand rule.  Point your thumb in the direction of the current flow and wrap your fingers around the wire.  Your fingers point in the direction of the magnetic field.  Fascinating, yes?  Well, okay, maybe not.  But this is.  You can wrap that wire around a metal rod.  Creating a solenoid.  And all those induced magnetic fields add up.  The more coils the greater the magnetic field.  That ‘flows’ in the same direction in that metal rod.  Creating an electromagnet out of that metal rod.  If you ever saw a crane in a junk yard picking up scrap metal with a magnet this is what’s happening.  The crane operator turns on an electromagnet to attract and hold that scrap metal.  And turns off the electromagnet to release that scrap metal.

A DC Electric Motor is Basically a Fixed Magnet Interacting with a Rotating Magnet

If that metal rod was free to move you get something completely different.  For when you pass a current through that coiled wire the magnetic force it creates will move that metal rod.  If it’s not restrained it will fly right out of the coil.  Which is interesting to see but not very useful.  But the ability to move a restrained metal rod at the flick of a switch can be very useful.  For we can use a solenoid to convert electrical energy into linear mechanical movement.  As in a transducer.  An electromechanical solenoid.  That takes an electrical input to generate a mechanical output.  Which we use in many things.  Like in a high-speed conveyor system that sorts things.  Like a baggage handling system at an airport.  Or in an order fulfillment center.  Where things fly down a conveyor belt while diverter gates move to route things to their ultimate destination.  If the gate is not activated the product stays on the main belt.  When a gate is activated a gate moves across the path of the main conveyor belt and diverts the product to a new conveyor line or a drop off.  And the things that operate those gates are electromechanical solenoids.  Or transducers.  Things that convert an electrical input to a mechanical output.  To produce a linear mechanical motion.  To move that gate.

Solenoids are useful.  A lot of things work because of them.  But there is only so much this linear motion can do.  Basically alternating between two states.  Open and closed.   In or out.
On or off.  Again, useful.  But of limited use.  However, we can use these same principles and create rotational motion.  Which is far more useful.  Because we can make electric motors with the rotational motion created by magnetic fields.  The first electric motors were direct current (DC).  And included two basic parts.  The stator.  And the rotor (or armature).  The stator creates a fixed magnetic field.  With permanent magnates.  Or one created with current passing through coiled wiring.  The armature is made up of multiple coils.  Each coil insulated and separate from the next one.  When an electric current goes through one of these rotor coils it creates an electromagnet.

So a DC electric motor is basically a fixed magnet interacting with a rotating magnet.  Current passes to the rotor winding through brushes in contact with the armature.  Like closing a switch.  Current flows in through one brush.  And out through another.  When current goes through one of these rotor coils it creates an electromagnet.  With a north and south pole.  As this magnetic field interacts with the fixed magnetic field produced by the stator there are forces of attraction and repulsion.  As the ‘like’ poles repel each other.  And the ‘unlike’ poles attract each other.  Causing the armature to turn.  After it turns the brushes ‘disconnect’ from that rotor wiring and ‘connect’ to the next rotor winding in the armature.  Creating a new electromagnet.  And new forces of repulsion and attraction.  Causing the armature to continue to turn.  And so on to produce useful rotational mechanical motion.

An Automobile Starter Motor combines an Electromechanical Solenoid and a DC Electric Motor

Everyone who has ever driven a car is thoroughly familiar with electromechanical solenoids and DC electric motors.  Because unlike our forefathers who had to use hand-cranks to start their cars we don’t.  All we have to do is turn a key.  Or press a button.  And that internal combustion engine starts turning.  Fuel begins to flow to the cylinders.  And electricity flows to the spark plugs.  Igniting that compressed fuel-air mixture in the cylinder.  Bringing that engine to life.

So what starts this process?  An electromechanical solenoid.  And a DC motor.  Packaged together in an automobile starter motor.  The other components that make this work are the starter ring gear on the flywheel (mounted to the engine to smooth out the rotation created by the reciprocating pistons) and the car battery.  When you turn the ignition key current flows from the battery to the electromechanical solenoid.  This linear motion operates a lever that moves a drive pinion out of the starter (while compressing a spring inside the starter), engaging it with the starter ring gear.  Current also flows into a DC motor inside the starter.  As this motor spins it rotates the starter ring gear on the flywheel.  As combustion takes place in the cylinders the pistons start reciprocating, turning the crankshaft.  At which time you let go of the ignition key.  Stopping the current flow through both the solenoid and the DC motor.  The starter stops spinning.  And that compressed spring retracts the drive pinion from the starter ring gear.  All happening in a matter of seconds.  So quick and convenient you don’t give it a second thought.  You just put the car in gear and head out on the highway.  And enjoy the open road.  Wherever it may take you.  For getting there is half the fun.  Or more.

Electric motors have come a long way since our first DC motors.  Thanks to the advent of AC power distribution and polyphase motors.  Brought to us by the great Nikola Tesla.  While working for the great George Westinghouse.  Pretty much any electric motor today is based on a Tesla design.  But little has changed on the automotive starter motor.  Because batteries are still DC.  And before a car starts that’s all there is.  Once it’s running, though, a polyphase AC generator produces all the electricity used after that.  A bridge rectifier converts the three phase AC current into DC.  Providing all the electric power the car needs.  Even charging the battery.  So it’s ready to spin that starter motor the next time you get into your car.

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Rotational Motion, Windmill, Waterwheel, Steam Engine, Compressed Air and Electric Power

Posted by PITHOCRATES - July 24th, 2013

Technology 101

The Combination of Force and Current of Moving Water on a Waterwheel produced Rotational Motion

Through most of history man has used animals for their source of power.  To do the heavy work in our advancing civilizations.  And they worked very well for linear work.  Going long distances in a straight line.  Such as pulling a carriage.  Or a plow.  Things done outdoors.  A long place typically from where people ate and slept.  So animal urine and feces wasn’t a great problem.  But the closer we brought them to our civilized parts of society it became a problem.  For it brought the smell, the flies and the disease closer to our civilized part of life.

Animals were good for linear work.  But as civilization advanced rotational work became more important.  For as machines advanced they needed to spin.  The more advanced machines needed to spin at a fairly high revolutions per minute (rpm).  We have used animals to produce rotational motion.  By having them walk in a small circle.  To slowly turn a mill stone.  Or some other rotational machine.  But it was inefficient.  As animals can’t work continuously.  Especially when walking in a circle.  They have to rest.  Eat.  And they have to urinate and defecate.  Making it unclean.  And unhealthy.

The first great industrial advance was water power.  Using a waterwheel.  Spun by a current of water.  Either a large force of water moving slow and steady.  Like in a river.  Or a small force of water moving fast and furiously.  Like in a small waterfall.  This combination of force and current produced rotational movement.  And useable power.  The waterwheel produced a rotational motion.  This rotational motion drove a main drive shaft through a factory.  Gear trains could speed up the rpm produced by a slow river current.  Or reduce the rpm produced by a fast waterfall current.  To produce a constant rotational speed.  That was strong enough to drive numerous loads attached to the main drive shaft via belts and pulleys.

Compressed Air Systems allowed us to produce Rotational Motion at our Workstations

Water power was a great advancement over animal power.  But it had one major drawback.  You needed a moving current of water.  Which meant we had to build our factories on the banks of rivers.  Or under a waterfall.  One of the reasons why our first industrial cities were on rivers.  The steam engine changed that.  With a steam engine providing our rotational motion we could put a factory pretty much anywhere.  And the power of steam could do a lot more work than a moving current of water.  So factories grew larger.  But they still relied on a rotating main drive shaft.  Then we started doing something else with our steam engines.  We began compressing air with them.

A current of air can fill masts of sails and push ships across oceans.  Air has mass.  So moving air has energy.  We’ve used windmills to turn millstones to crush our wheat.  Where a large force of a slow moving wind current filled a sail.  And pushed.  But these small currents of air required large sails.  If we compressed that volume of air down and pushed it through a very small air hose we could get a force at the end of that hose similar to what we got with a sail catching a large volume of air.  This allowed us to create rotational motion at a workstation.  Without the need of a rotating main drive shaft.  We could connect an air hose to a handheld drill.  And the compressed air in the air hose could direct a jet of high pressure air onto an ‘air-wheel’ inside the handheld drill.  Which spun the ‘air-wheel’ at a very high rpm.  Spinning the drill bit at a very high rpm.

Compressed air was a great advancement over a rotating main drive shaft.  Instead of belts and pulleys connecting to the main shaft you just had to plug in your pneumatic tool to an air line.  The steam engine’s rotational motion would drive an air compressor.  Typically turning a crankshaft with two pistons attached to it.  When a piston moves down the cylinder it draws air into the cylinder.  When the piston moves up it compresses the air in the cylinder.  The compressed air exits the cylinder and enters a large air tank.  From this air tank they run a network of pipes throughout the factory.  From these pipes hang air hoses with fittings that prevent the air from leaking out.  Keeping the whole system charged under pressure.  Then a worker takes his pneumatic tool.  Plugs it into the fitting on a hanging air hose.  As they snapped together you’ll hear a rush of air blow out.  But once they snap together the joined fittings became airtight.  When the worker presses the trigger on the pneumatic tool the compressed air blows out at a very high current.  Spinning an ‘air-wheel’ that provides useful rotational
motion.

Electric Power generated Rotational Motion eliminated the need of Steam Engines and Compressed Air Systems

As good as this was there were some drawbacks.  It takes time to produce steam when you first start up a steam engine.  Once you have built up steam pressure then you can start producing rotational motion so the air compressor can start compressing air.  This takes time, too.  Then you need a lot of piping to push that air through.  A piping system than can leak.  It was a great system.  But there was room for improvement.  And this last improvement we made was so good that we haven’t made another in over 100 years.  A new way to provide rotational motion at a workstation.  Without requiring a steam boiler.  And air compressor.  Or a vast piping system charged with air pressure.  Something that allows us to plug in and go right to work.  Without waiting for steam or air pressure to build.  And that last advancement was, of course, electric power.

When voltage (force) pushes an electrical current through a wire we get useable power.  Generators at a distant power plant produce voltages that push current through wires.  And these wires can run anywhere.  In the air.  Or underground.  They can travel great distances at dangerous high voltages and low currents.  And we can use transformers to change them to a safer low voltage and a higher current in our factories.  And our homes.  Where we can use that force and current to produce useful rotational motion.  Using electric and magnetic fields inside an electrical motor.

Animals were a poor source of rotational power.  The windmill and the waterwheel were better.  The windmill could go anywhere but the rotational motion was only available when the wind blew.  Waterwheels provided continuous rotational motion but they only worked where there was moving water.  Keeping our early factories on the rivers.  The steam engine let us build factories where there was no moving water.  While an air compressor driven by a steam engine made it much easier to transfer power form the power source to the workstation.  While electric power made that transfer easier still.  It also eliminated the need of the steam engine and the pneumatic piping system.  Allowing us to create rotational motion right at the point of work.  With the ease of plugging in.  And pressing a trigger.  Allowing machines to enter our homes to make our lives easier.  Like the vacuum cleaner.  The clothes washer.  And the air conditioner.  None of which your average homeowner could operate if we depended on a main drive shaft in our house.  Or a steam engine driving a pneumatic system.

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The Horse, Waterwheel, Steam Engine, Electricity, DC and AC Power, Power Transmission and Electric Motors

Posted by PITHOCRATES - December 26th, 2012

Technology 101

(Original published December 21st, 2011)

A Waterwheel, Shaft, Pulleys and Belts made Power Transmission Complex

The history of man is the story of man controlling and shaping our environment.  Prehistoric man did little to change his environment.  But he started the process.  By making tools for the first time.  Over time we made better tools.  Taking us into the Bronze Age.  Where we did greater things.  The Sumerians and the Egyptians led their civilization in mass farming.  Created some of the first food surpluses in history.  In time came the Iron Age.  Better tools.  And better plows.  Fewer people could do more.  Especially when we attached an iron plow to one horsepower.  Or better yet, when horses were teamed together to produce 2 horsepower.  3 horsepower.  Even 4 horsepower.  The more power man harnessed the more work he was able to do.

This was the key to controlling and shaping our environment.  Converting energy into power.  A horse’s physiology can produce energy.  By feeding, watering and resting a horse we can convert that energy into power.  And with that power we can do greater work than we can do with our own physiology.  Working with horse-power has been the standard for millennia.  Especially for motive power.  Moving things.  Like dragging a plow.  But man has harnessed other energy.  Such as moving water.  Using a waterwheel.  Go into an old working cider mill in the fall and you’ll see how man made power from water by turning a wheel and a series of belts and pulleys.  The waterwheel turned a main shaft that ran the length of the work area.  On the shaft were pulleys.  Around these pulleys were belts that could be engaged to transfer power to a work station.  Where it would turn another pulley attached to a shaft.  Depending on the nature of the work task the rotational motion of the main shaft could be increased or decreased with gears.  We could change it from rotational to reciprocating motion.  We could even change the axis of rotation with another type of gearing.

This was a great step forward in advancing civilization.  But the waterwheel, shaft, pulleys and belts made power transmission complex.  And somewhat limited by the energy available in the moving water.  A great step forward was the steam engine.  A large external combustion engine.  Where an external firebox heated water to steam.  And then that steam pushed a piston in a cylinder.  The energy in expanding steam was far greater than in moving water.  It produced far more power.  And could do far more work.  We could do so much work with the steam engine that it kicked off the Industrial Revolution.

Nikola Tesla created an Electrical Revolution using AC Power

The steam engine also gave us more freedom.  We could now build a factory anywhere we wanted to.  And did.  We could do something else with it, too.  We could put it on tracks.  And use it to pull heavy loads across the country.  The steam locomotive interconnected the factories to the raw materials they consumed.  And to the cities that bought their finished goods.  At a rate no amount of teamed horses could equal.  Yes, the iron horse ended man’s special relationship with the horse.  Even on the farm.  Where steam engines powered our first tractors.  Giving man the ability to do more work than ever.  And grow more food than ever.  Creating greater food surpluses than the Sumerians and Egyptians could ever grow.  No matter how much of their fertile river banks they cultivated.  Or how much land they irrigated.

Steam engines were incredibly powerful.  But they were big.  And very complex.  They were ideal for the farm and the factory.  The steam locomotive and the steamship.  But one thing they were not good at was transmitting power over distances.  A limitation the waterwheel shared.  To transmit power from a steam engine required a complicated series of belts and pulleys.  Or multiple steam engines.  A great advance in technology changed all that.  Something Benjamin Franklin experimented with.  Something Thomas Edison did, too.  Even gave us one of the greatest inventions of all time that used this new technology.  The light bulb.  Powered by, of course, electricity.

Electricity.  That thing we can’t see, touch or smell.  And it moves mysteriously through wires and does work.  Edison did much to advance this technology.  Created electrical generators.  And lit our cities with his electric light bulb.  Electrical power lines crisscrossed our early cities.  And there were a lot of them.  Far more than we see today.  Why?  Because Edison’s power was direct current.  DC.  Which had some serious drawbacks when it came to power transmission.  For one it didn’t travel very far before losing much of its power. So electrical loads couldn’t be far from a generator.  And you needed a generator for each voltage you used.  That adds up to a lot of generators.  Great if you’re in the business of selling electrical generators.  Which Edison was.  But it made DC power costly.  And complex.  Which explained that maze of power lines crisscrossing our cities.  A set of wires for each voltage.  Something you didn’t need with alternating current.  AC.  And a young engineer working for George Westinghouse was about to give Thomas Edison a run for his money.  By creating an electrical revolution using that AC power.  And that’s just what Nikola Tesla did.

Transformers Stepped-up Voltages for Power Transmission and Stepped-down Voltages for Electrical Motors

An alternating current went back and forth through a wire.  It did not have to return to the electrical generator after leaving it.  Unlike a direct current ultimately had to.  Think of a reciprocating engine.  Like on a steam locomotive.  This back and forth motion doesn’t do anything but go back and forth.  Not very useful on a train.  But when we convert it to rotational motion, why, that’s a whole other story.  Because rotational motion on a train is very useful.  Just as AC current in transmission lines turned out to be very useful.

There are two electrical formulas that explain a lot of these developments.  First, electrical power (P) is equal to the voltage (V) multiplied by the current (I).  Expressed mathematically, P = V x I.  Second, current (I) is equal to the voltage (V) divided by the electrical resistance (R).  Mathematically, I = V/R.  That’s the math.  Here it is in words.  The greater the voltage and current the greater the power.  And the more work you can do.  However, we transmit current on copper wires.  And copper is expensive.  So to increase current we need to lower the resistance of that expensive copper wire.  But there’s only one way to do that.  By using very thick and expensive wires.  See where we’re going here?  Increasing current is a costly way to increase power.  Because of all that copper.  It’s just not economical.  So what about increasing voltage instead?  Turns out that’s very economical.  Because you can transmit great power with small currents if you step up the voltage.  And Nikola Tesla’s AC power allowed just that.  By using transformers.  Which, unfortunately for Edison, don’t work with DC power.

This is why Nikola Tesla’s AC power put Thomas Edison’s DC power out of business.  By stepping up voltages a power plant could send power long distances.  And then that high voltage could be stepped down to a variety of voltages and connected to factories (and homes).  Electric power could do one more very important thing.  It could power new electric motors.  And convert this AC power into rotational motion.  These electric motors came in all different sizes and voltages to suit the task at hand.  So instead of a waterwheel or a steam engine driving a main shaft through a factory we simply connected factories to the electric grid.  Then they used step-down transformers within the factory where needed for the various work tasks.  Connecting to electric motors on a variety of machines.  Where a worker could turn them on or off with the flick of a switch.  Without endangering him or herself by engaging or disengaging belts from a main drive shaft.  Instead the worker could spend all of his or her time on the task at hand.  Increasing productivity like never before.

Free Market Capitalism gave us Electric Power, the Electric Motor and the Roaring Twenties

What electric power and the electric motor did was reduce the size and complexity of energy conversion to useable power.  Steam engines were massive, complex and dangerous.  Exploding boilers killed many a worker.  And innocent bystander.  Electric power was simpler and safer to use.  And it was more efficient.  Horses were stronger than man.  But increasing horsepower required a lot of big horses that we also had to feed and care for.  Electric motors are smaller and don’t need to be fed.  Or be cleaned up after, for that matter.

Today a 40 pound electric motor can do the work of one 1,500 pound draft horse.  Electric power and the electric motor allow us to do work no amount of teamed horses can do.  And it’s safer and simpler than using a steam engine.  Which is why the Roaring Twenties roared.  It was in the 1920s that this technology began to power American industry.  Giving us the power to control and shape our environment like never before.  Vaulting America to the number one economic power of the world.  Thanks to free market capitalism.  And a few great minds along the way.

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Waterwheel, Rotational Motion, Reciprocal Motion, Steam Engine, Internal Combustion Engine and Hydraulic Brakes

Posted by PITHOCRATES - December 5th, 2012

Technology 101

To Keep People on Trains they Undercharge Passengers and make up the Difference with Government Subsidies

We built some of our first factories on or near a river.  Where we could use that river’s current to turn a waterwheel.  To provide a rotational motion that could do work for us.  We transmitted that rotational motion via a main drive shaft through a factory where it could drive machinery via belts and pulleys.  Once we developed the steam engine to provide that rotational motion we could move our factories anywhere.  Not just on or near a river.  Giving us greater freedom.  And permitting greater economic growth.  As we put those steam engines onto rails.  That transported freight and people all across the country.

Trains are nice.  But expensive.  To go anywhere on a train you need train tracks going there.  But train tracks are incredibly expensive to lay.  And maintain.  If you ever stared at a set of train tracks you probably noticed something.  There aren’t a lot of trains going by on them.  When a train stops you when you’re running late or bringing home dinner it may feel like trains are always stopping you.  But if you parked at those same tracks for a few hours you wouldn’t see a lot of trains.  Because even the most polished rails (the more train traffic the more polished the rails) are unused more than they are used.

This is why trains are very expensive.  Tracks cost a lot of money to lay and maintain.  Costs that a railroad has to recoup from trains using those rails.  And when you don’t have a lot of trains on those rails you have to charge a lot for the trains that do travel on them.  A mile-long train pulling heavy freight can pay a lot of revenue.  And make a railroad profitable.  But passenger trains are not a mile long.  And carry few people.  Which means to make money on a passenger train you’d have to charge more for a ticket than people would pay.  To keep people on trains, then, they have to undercharge passengers.  And make up the difference with government subsidies.

A Crank Shaft and Combustion Timing takes Reciprocal Motion of Pistons and Converts it into Rotational Motion

This is why people drive places instead of taking the train.  It’s far less expensive to take the car.  And there are roads everywhere.  Built and maintained by gas taxes, licenses and fees.  And if you’ve ever driven on a road you probably noticed that there are a lot of cars, motorcycles, trucks and buses around you.  With so many vehicles on the roads they each can pay a small amount to build and maintain them.  Which is something the railroads can’t do.  Only trains can travel on train tracks.  But cars, motorcycles, trucks and buses can all travel on roads.  This is why driving a car is such a bargain.  Economies of scale.

To operate a train requires a massive infrastructure.  Dispatchers control the movement of every train.  Tracks are broken down into blocks.  The dispatchers allow only one train in a block at a time.  They do this for a couple of reasons.  Trains don’t have steering wheels.  And can take up to a mile to stop.  So to operate trains safely requires keeping them as far apart from each other as possible.  Traveling on roads is a different story.  There are no dispatchers separating traffic.  Cars, motorcycles, trucks and buses travel very close together.  Starting and stopping often.  Traveling up to high speeds between traffic lights.  With motorcycles and cars weaving in and out among trucks and buses.  Avoiding traffic and accidents by speeding up and slowing down.  And steering.

Driving a car today is something just about anyone 16 and older can do.  Thanks to the remarkable technology that makes a car.  Starting with the internal combustion engine.  The source of power that makes everything possible.  Just like those early waterwheels the source of that power is rotational motion.  But instead of a river providing the energy an internal combustion engine combusts gasoline to push pistons.  A crank shaft and combustion timing takes that reciprocal motion of the pistons and converts it into rotational motion.  Spinning a drive shaft that provides power to drive the car.  As well as power all of its accessories.

The Friction of Brake Shoe or Pad on Steel slows the Car converting Kinetic Energy into Heat

The first cars required a lot of man-power.  It took great strength to rotate the hand-crank to start the engine.  Sometimes the engine would spit and cough.  And kick back.  Breaking the occasional wrist.  Once started it took some leg-power to depress the clutch to shift gears.  It took a little upper body strength to turn the steering wheel.  And some additional leg-power to apply the brakes to stop the car.  In time we replaced the hand-crank with the electric starter.  We replaced the clutch and gearbox with the automatic transmission.  We added power steering and power breaks to further reduce the amount of man-power needed to drive a car.  Today a young lady in high heels and a miniskirt can drive a car as easily and as expertly as the first pioneers who risked bodily harm to drive our first cars.

The internal combustion engine can spin a crankshaft very fast and accelerate a car to great speeds.  Which is good for darting in and out of traffic.  But traffic occasional has to stop.  Which is easier said than done.  For a heavy car moving at speed has a lot of kinetic energy.  You can’t destroy energy.  You can only convert it.  And in the case of slowing down a car you have to convert that kinetic energy into heat.  When you press the brake pedal you force hydraulic fluid from a master cylinder to small cylinders at each wheel.  As fluids cannot compress when you apply a force to the fluid that force is transmitted to something than can move.  In the case of stopping a car it is either a brake shoe that presses against the inside of the car’s wheels.  Or a caliper that clamps down on a disc.  The friction of brake shoe or pad on steel slows the car.  Converting that kinetic energy into heat.  In some cases of excessive braking (on a train or a plane) the heat can be so excessive that the wheels or discs glow red.

So as the internal combustion engine and the brakes play their little games of speeding up and slowing down a car the rotational power of the crankshaft drives other accessories.  Such as power steering.  Where a belt and pulley transfers that rotational power to a power steering pump.  The pump pushes fluid to the steering gear to assist in turns.  Another belt and pulley connects an alternator to the crankshaft to produce electricity to provide power for the car’s electrical systems.  And to charge the battery so it can spin the automatic starter.  Another belt and pulley connects another compressor to the crankshaft.  This one for air conditioning.  That allows us to alight from our cars shower-fresh on the hottest and most humid days of the year.  And, finally, antifreeze removes the heat of combustion from the internal combustion engine and transfers it to a heating core inside the passenger compartment.  Allowing a warm and comfortable drive home during the coldest of days.  As well as keeping our windows free of snow and ice so we can see to drive safely on our way home.  Through bumper to bumper traffic.  Something we do day after day with the ease of doing the laundry.  Thanks to the remarkable technology that we take for granted that makes a car.

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Animal Power, Waterwheel, Ship Transport, Steam Engine, Railroad, Steel Industry, Robotics, Rust Belt and Minimills

Posted by PITHOCRATES - November 14th, 2012

Technology 101

Rent-Seeking Captains of Industry and Commerce give Capitalism a Bad Name

Once upon a time you lived, worked and died all within a short walk from each other.  In feudalism people owned land and lived well.  The landed aristocracy.  And other people (the peasants) worked the land.  But did not live as well as those who owned it.  For it was back-breaking work for long hours with no respite except in death.  For those who worked the land belonged to the land.  Just as the trees and fields and rivers did.  Peasants belonged to the land and the land belonged to the landowner.  The peasants couldn’t leave.  And they couldn’t work hard to provide a better life for their children.  For they were bond to the land as their patents were.  With no choice but to work the land like their parents did.

This was how life was before we started to use power to make our work easier.  We had long been using animal power to do things we didn’t have the strength or the endurance to do.  Such as pulling a plow.  Or a wagon full of goods.  Or to travel great distances more quickly than we could by walking.  Harnessing the power of moving water changed all of that.  For a river moves constantly.  And when you place a waterwheel in moving water you can convert the linear motion of the water into rotational motion.  This rotational motion could turn a main shaft running though a factory.  Belts and pulleys could transfer this power to workstations throughout the factory floor.  And these powered workstations could do far more work than a person could.  Lumberjacks could transport logs down a river to a lumber mill.  Where a waterwheel could spin a saw that made lumber out of those logs at such a rate that great cities could arise around these mills.  Cities with other factories powered by waterwheels.  And homes.

So it’s no surprise that our early cities grew up on rivers.  Both for water power.  And the ability to use them to ship bulk goods.  Ship transport.  Something even animals weren’t good at.  It is in these cities that wealth and political power grew.  Centers of industry and commerce.  Creating great wealth for those who controlled the resources that made all of that possible.  So another aristocracy grew.  Rent-seeking captains of industry and commerce.  Who give capitalism a bad name.  Who use their political power to maximize their profits.  And buy favors from those in power to protect their particular interests.  Such as using the power of government to create monopolies for themselves.  But advancing technology made that harder to do.  Especially the steam engine.  And the railroad.

The Steel and Heavy Manufacturing Industries required a Massive Infrastructure and Regionally Located Raw Materials

Control of rivers, ports and harbors provided a great opportunity to amass wealth at other people’s expense.  For when economic activity centered on water it made land around that water very valuable.  Which concentrated wealth and power on the rivers.  Until the steam engine replaced the waterwheel.  And the railroad provided a way to transport people and goods inland.  So not only did cities grow up along the waterways they grew up along the rail lines.  Those controlling these resources still had great wealth and power.  But they also offered competition.  And more economic liberty.  For while there can only be one Tennessee River flowing through Chattanooga, Tennessee, there can be more than one railroad running through Chattanooga.  Which made Chattanooga an important city to hold during the American Civil War.  For there was a great rail junction in that city.  Giving anyone who controlled the city access to any part of the Confederacy.

While the steam engine and railroad allowed industries to grow anywhere in the country some industries still clustered in regional areas.  Such as the steel industry.  It required three ingredients to make steel.  Iron ore, coke (coal cooked into hard charcoal briquettes) and limestone.  To make steel you use 6 parts iron ore, 2 parts coke and 1 part limestone.  Iron ore was plentiful around Lake Superior.  Because it takes a lot of iron ore and a lot of iron ore is located around Lake Superior the steel makers built their mills long the Great Lakes.  In Milwaukee.  Chicago.  Gary.  Detroit.  Toledo.  Cleveland.  Or in places like Pittsburgh where coal and iron ore deposits surround the city.  These cities made up the Manufacturing Belt.  Places with access to bulk ore shipping (on Great Lakes freighter or river barge).  And where the steel mills arose so did heavy industry that built things from that steel.  From structural steel.  To automobiles.

For a while these new industries dominated the economic landscape.  Big, heavy industries that couldn’t move.  Concentrating money and political power.  Giving rise to organized labor.  Who took advantage of the fact that these heavy industries could not move.  Negotiating lucrative union contracts.  With generous pay and benefits.  Raising the price of steel and the things we made from steel.  Like automobiles.  Making the rank and file like rent-seekers of old.  Looking to personally benefit from their near-monopoly conditions.  Like those early captains of industry and commerce.  Life was good for awhile for the rank and file.  Who lived very well.  And better than most American workers.  Thanks to those monopoly-like conditions in these steel and heavy manufacturing industries.  Allowing them to charge high prices for their goods to pay for those generous pay and benefits.  As there was no competition.  For the steel and heavy manufacturing industries required a massive infrastructure and an abundant supply of regionally located raw materials, making it very difficult for a new competitor to open for business.  At least, in the United States.

High Costs and Low Efficiencies have shuttered most of America’s Steel Making Past

Foreign competition changed all that.  And large ocean-going ships.  So new industries in other countries with lower labor costs could manufacture these goods and ship them to the United States.  And did.  Challenging the monopoly-like conditions of the rent-seeking steel and heavy manufacturing industries.  So the rent-seekers turned to government for protection.  And got it.  Import tariffs.  Which raised the price of those imported goods to the higher price level of the domestic goods.  Which did two things.  Insulated the domestic manufacturers from market pressures allowing them to continue with the status quo.  And forced the foreign manufacturers to find less costly and more efficient ways to make their goods to counter those import tariffs.

So what happened?  Technology advanced in these industries overseas while they stagnated in the US.  The US didn’t invest in new technologies like they did in the previous century to find better ways to do things.  Because they didn’t have to.  While the foreign competitors worked harder to find better ways to do things.  Because they had to.  As they weren’t insulated from market forces.  The Japanese invested in robotics.  Transforming their auto industry.  Improving quality and lowering costs.  Making their cars as good if not better than the Americans did.  And selling them at a competitive price even with those import protections.  So what did these US actions to protect the domestic manufacturers do?  Changed the Manufacturing Belt to the Rust Belt.

The big steel cities in America are no more.  High costs and low efficiencies have shuttered most of America’s steel making past.  Gone is the era of the sprawling steel mill.  Today it’s the minimill and continuous casting.  Small and efficient steel mills with small labor forces that can make small batches.  Thanks to their electric arc furnaces that are easy to turn on and off.  Unlike the big blast furnaces that took a while to reach operating temperatures and when they did they didn’t shut them down for years.  Making it difficult to adjust to falling demand.  Like the minimills could.  Which helped save the steel industry by finally adopted technology that allowed it to sell at market prices.  Making it harder for the rent-seekers these days.  But better for consumers.  Because of this relentless march of technology.  That allows us to continuously find better ways to do things.

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Windmills, Waterwheels, Steam Engine, Electric Power, Coal, Heat Engine, Steam Turbine, Generator and Coal-Fired Power Plant

Posted by PITHOCRATES - July 11th, 2012

Technology 101

By burning Coal to Boil Water into Steam to Move a Piston we could Build a Factory Anywhere

We created advanced civilization by harnessing energy.  And converting this energy into working power.  Our first efforts were biological.  Feeding and caring for large animals made these animals strong.  Their physiology converted food and water into strong muscles and bones.  Allowing them to pull heavy loads.  From plowing.  To heavy transportation.  To use in construction.  Of course the problem with animals is that they’re living things.  They eat and drink.  And poop and pee.  Causing a lot of pollution in and around people.  Inviting disease.

As civilization advanced we needed more energy.  And we found it in wind and water.  We built windmills and waterwheels.  To capture the energy in moving wind and moving water.  And converted this into rotational motion.  Giving us a cleaner power source than working animals.  Power that didn’t have to rest or eat.  And could run indefinitely as long as the wind blew and the water flowed.  Using belts, pulleys, cogs and gears we transferred this rotational power to a variety of work stations.  Of course the problem with wind and water is that you needed to be near wind and water.  Wind was more widely available but less reliable.  Water was more reliable but less widely available.  Each had their limitations.

The steam engine changed everything.  By burning a fuel (typically coal) to boil water into steam to move a piston we could build a factory anywhere.  Away from rivers.  And even in areas that had little wind.  The reciprocating motion of the piston turned a wheel to convert it into rotational motion.  Using belts, pulleys, cogs and gears we transferred this rotational power to a variety of work stations.  This carried us through the Industrial Revolution.  Then we came up with something better.  The electric motor.  Instead of transferring rotational motion to a workstation we put an electric motor at the work station.  And powered it with electricity.  Using electric power to produce rotational motion at the workstation.  Electricity and the electric motor changed the world just as the steam engine had changed the world earlier.  Today the two have come together.

You can tell a Power Plant uses a Scrubber by the White Steam puffing out of a Smokestack

Coal has a lot of energy in it.  When we burn it this energy is transformed into heat.  Hot heat.  For coal burns hot.  The modern coal-fired power plant is a heat engine.  It uses the heat from burning coal to boil water into steam.  And as steam expands it creates great pressure.  We can use this pressure to push a piston.  Or turn a steam turbine.  A rotational device with fins.  As the steam pushes on these fins the turbine turns.  Converting the high pressure of the steam into rotational motion.  We then couple this rotational motion of the steam turbine to a generator.  Which spins the generator to produce electricity.

Coal-fired power plants are hungry plants.  A large plant burns about 1,000 tons of coal an hour.  Or about 30,000 pounds a minute.  That’s a lot of coal.  We typically deliver coal to these plants in bulk.  Via Great Lakes freighters.  River barges.  Or unit trains.  Trains made up of nothing but coal hopper cars.  These feed coal to the power plants.  They unload and conveyor systems take this coal and create big piles.  You can see conveyors rising up from these piles of coal.  These conveyors transport this coal to silos or bunkers.  Further conveyor systems transfer the coal from these silos to the plant.  Where it is smashed and pulverized into a dust.  And then it’s blown into the firebox, mixed with hot air and ignited.  Creating enormous amounts of heat to boil an enormous amount of water.  Creating the steam to turn a turbine.

Of course, with combustion there are products left over.  Sulfur impurities in the coal create sulfur dioxide.  And as the coal burns it leaves behind ash.  A heavy ash that falls to the bottom of the firebox.  Bottom ash.  And a lighter ash that is swept away with the flue gases.  Fly ash.  Filters catch the fly ash.  And scrubbers use chemistry to remove the sulfur dioxide from the flue gases.  By using a lime slurry.  The flue gases rise through a falling mist of lime slurry.  They chemically react and create calcium sulfate.  Or Gypsum.  The same stuff we use to make drywall out of.  You can tell a power plant uses a scrubby by the white steam puffing out of a smokestack.  If you see great plumes puffing out of a smokestack there’s little pollution entering the atmosphere.  A smokestack that isn’t puffing out a plume of white steam is probably spewing pollution into the atmosphere.

Coal is a Highly Concentrated Source of Energy making Coal King when it comes to Electricity

When the steam exits the turbines it enters a condenser.  Which cools it and lowers its temperature and pressure.  Turning the steam back into water.  It’s treated then sent back to the boiler.  However, getting the water back into the boiler is easier said than done.  The coal heats the water into a high pressure steam.  So high that it’s hard for anything to enter the boiler.  So this requires a very powerful pump to overcome that pressure.  In fact, this pump is the biggest pump in the plant.  Powered by electric power.  Or steam.  Sucking some 2-3 percent of the power the plant generates.

Coupled to the steam turbine is a power plant’s purpose.  Generators.  Everything in a power plant serves but one purpose.  To spin these generators.  And when they spin they generate a lot of power.  Producing some 40,000 amps at 10,000 to 30,000 volts at a typical large plant.  Multiplying current by power and you get some 1,200 MW of power.  Which can feed a lot of homes with 100 amp, 240 volt services.  Some 50,000 with every last amp used in their service.  Or more than twice this number under typical loads.  Add a few boilers (and turbine and generator sets) and one plant can power every house and business across large geographic areas in a state.  Something no solar array or wind farm can do.  Which is why about half of all electricity produced in the U.S. is generated by coal-fired power plants.

Coal is a highly concentrated source of energy.  A little of it goes a long way.  And a lot of it produces enormous amounts of electric power.  Making coal king when it comes to electricity.  There is nothing that can match the economics and the logistics of using coal.  Thanks to fracking, though, natural gas is coming down in price.  It can burn cleaner.  And perhaps its greatest advantage over coal is that we can bring a gas-fired plant on line in a fraction amount of the time it takes to bring a coal-fired plant on line.  For coal-fired plants are heat engines that boil water into steam to spin turbines.  Whereas gas-fired plants use the products of combustion to spin their turbines.  Utilities typically use a combination of coal-fired and gas-fired plants.  The coal-fired plants run all of the time and provide the base load.  When demand peaks (when everyone turns on their air conditioners in the evening) the gas-fired plants are brought on line to meet this peak demand.

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Magnets, Magnetic Field, Electromagnet, Electromechanical Solenoid, Stator, Armature, DC Electric Motor and Automobile Starter Motor

Posted by PITHOCRATES - April 18th, 2012

Technology 101

Electric Current flowing through a Wire can Induce Magnetic Fields Similar to those Magnets Create

We’ve all played with magnets as children.  And even as children we’ve observed things.  If you placed a bar magnet on a table and approached it with another one in your hand one of two things would happen.  As the magnets approached each other the one on the table would either move towards the other magnet.  Or away from the other magnet.  That’s because all magnets are dipoles.  That is, they have two poles.  A north pole.  And a south pole. 

These poles produce a magnetic field.  Outside of the magnet this field ‘flows’ from north to south.  Inside the magnet it ‘flows’ from south to north.  So imagine this magnetic force traveling through the magnet from south to north and right out of the north pole of the magnet.  Where it then bends around and heads back to the south pole.  Something most of us saw as children.  When we placed a piece of paper with iron filings over a bar magnet.  As we placed the paper over the magnet the iron filings moved.  They formed in lines.  That followed the magnetic field created by the magnetic dipole.  You can’t see the direction of the field but it only ‘flows’ in one direction.  As noted above.  If the north pole of one magnet is placed near the south pole of another the magnetic field ‘flows’ from the north pole of one magnet to the south pole of the other magnet.  Pulling them together.  If both north poles or both south poles are placed near each other they will repulse each other.  Because the magnetic field is ‘flowing’ out from each north pole.  Or into each south pole.  The magnets repulse each other because the magnetic field is trying to flow from north to south.  If one magnet was able to rotate this repulsion would rotate the magnet about 90 degrees.  To try and align one north pole with one south pole.  As the momentum pushed the magnet past the 90 degree point the force would reverse to attraction.  Rotating the magnet about another 90 degrees.  Where it will then stop.  Having aligned a north and a south pole. 

It turns out this ability to move things with magnetic fields is very useful.  Both in linear motion.  And rotational motion.  Especially after we observed we could create magnetic fields by passing an electric current through a wire.  When you do a magnetic field circles the wire.  To determine which direction you simply use the right-hand rule.  Point your thumb in the direction of the current flow and wrap your fingers around the wire.  Your fingers point in the direction of the magnetic field.  Fascinating, yes?  Well, okay, maybe not.  But this is.  You can wrap that wire around a metal rod.  Creating a solenoid.  And all those induced magnetic fields add up.  The more coils the greater the magnetic field.  That ‘flows’ in the same direction in that metal rod.  Creating an electromagnet out of that metal rod.  If you ever saw a crane in a junk yard picking up scrap metal with a magnet this is what’s happening.  The crane operator turns on an electromagnet to attract and hold that scrap metal.  And turns off the electromagnet to release that scrap metal.

A DC Electric Motor is Basically a Fixed Magnet Interacting with a Rotating Magnet

If that metal rod was free to move you get something completely different.  For when you pass a current through that coiled wire the magnetic force it creates will move that metal rod.  If it’s not restrained it will fly right out of the coil.  Which is interesting to see but not very useful.  But the ability to move a restrained metal rod at the flick of a switch can be very useful.  For we can use a solenoid to convert electrical energy into linear mechanical movement.  As in a transducer.  An electromechanical solenoid.  That takes an electrical input to generate a mechanical output.  Which we use in many things.  Like in a high-speed conveyor system that sorts things.  Like a baggage handling system at an airport.  Or in an order fulfillment center.  Where things fly down a conveyor belt while diverter gates move to route things to their ultimate destination.  If the gate is not activated the product stays on the main belt.  When a gate is activated a gate moves across the path of the main conveyor belt and diverts the product to a new conveyor line or a drop off.  And the things that operate those gates are electromechanical solenoids.  Or transducers.  Things that convert an electrical input to a mechanical output.  To produce a linear mechanical motion.  To move that gate.

Solenoids are useful.  A lot of things work because of them.  But there is only so much this linear motion can do.  Basically alternating between two states.  Open and closed.   In or out.  On or off.  Again, useful.  But of limited use.  However, we can use these same principles and create rotational motion.  Which is far more useful.  Because we can make electric motors with the rotational motion created by magnetic fields.  The first electric motors were direct current (DC).  And included two basic parts.  The stator.  And the rotor (or armature).  The stator creates a fixed magnetic field.  With permanent magnates.  Or one created with current passing through coiled wiring.  The armature is made up of multiple coils.  Each coil insulated and separate from the next one.  When an electric current goes through one of these rotor coils it creates an electromagnet. 

So a DC electric motor is basically a fixed magnet interacting with a rotating magnet.  Current passes to the rotor winding through brushes in contact with the armature.  Like closing a switch.  Current flows in through one brush.  And out through another.  When current goes through one of these rotor coils it creates an electromagnet.  With a north and south pole.  As this magnetic field interacts with the fixed magnetic field produced by the stator there are forces of attraction and repulsion.  As the ‘like’ poles repel each other.  And the ‘unlike’ poles attract each other.  Causing the armature to turn.  After it turns the brushes ‘disconnect’ from that rotor wiring and ‘connect’ to the next rotor winding in the armature.  Creating a new electromagnet.  And new forces of repulsion and attraction.  Causing the armature to continue to turn.  And so on to produce useful rotational mechanical motion.

An Automobile Starter Motor combines an Electromechanical Solenoid and a DC Electric Motor

Everyone who has ever driven a car is thoroughly familiar with electromechanical solenoids and DC electric motors.  Because unlike our forefathers who had to use hand-cranks to start their cars we don’t.  All we have to do is turn a key.  Or press a button.  And that internal combustion engine starts turning.  Fuel begins to flow to the cylinders.  And electricity flows to the spark plugs.  Igniting that compressed fuel-air mixture in the cylinder.  Bringing that engine to life.

So what starts this process?  An electromechanical solenoid.  And a DC motor.  Packaged together in an automobile starter motor.  The other components that make this work are the starter ring gear on the flywheel (mounted to the engine to smooth out the rotation created by the reciprocating pistons) and the car battery.  When you turn the ignition key current flows from the battery to the electromechanical solenoid.  This linear motion operates a lever that moves a drive pinion out of the starter (while compressing a spring inside the starter), engaging it with the starter ring gear.  Current also flows into a DC motor inside the starter.  As this motor spins it rotates the starter ring gear on the flywheel.  As combustion takes place in the cylinders the pistons start reciprocating, turning the crankshaft.  At which time you let go of the ignition key.  Stopping the current flow through both the solenoid and the DC motor.  The starter stops spinning.  And that compressed spring retracts the drive pinion from the starter ring gear.  All happening in a matter of seconds.  So quick and convenient you don’t give it a second thought.  You just put the car in gear and head out on the highway.  And enjoy the open road.  Wherever it may take you.  For getting there is half the fun.  Or more.

Electric motors have come a long way since our first DC motors.  Thanks to the advent of AC power distribution and polyphase motors.  Brought to us by the great Nikola Tesla.  While working for the great George Westinghouse.  Pretty much any electric motor today is based on a Tesla design.  But little has changed on the automotive starter motor.  Because batteries are still DC.  And before a car starts that’s all there is.  Once it’s running, though, a polyphase AC generator produces all the electricity used after that.  A bridge rectifier converts the three phase AC current into DC.  Providing all the electric power the car needs.  Even charging the battery.  So it’s ready to spin that starter motor the next time you get into your car.

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The Horse, Waterwheel, Steam Engine, Electricity, DC and AC Power, Power Transmission and Electric Motors

Posted by PITHOCRATES - December 21st, 2011

Technology 101

A Waterwheel, Shaft, Pulleys and Belts made Power Transmission Complex

The history of man is the story of man controlling and shaping our environment.  Prehistoric man did little to change his environment.  But he started the process.  By making tools for the first time.  Over time we made better tools.  Taking us into the Bronze Age.  Where we did greater things.  The Sumerians and the Egyptians led their civilization in mass farming.  Created some of the first food surpluses in history.  In time came the Iron Age.  Better tools.  And better plows.  Fewer people could do more.  Especially when we attached an iron plow to one horsepower.  Or better yet, when horses were teamed together to produce 2 horsepower.  3 horsepower.  Even 4 horsepower.  The more power man harnessed the more work he was able to do.

This was the key to controlling and shaping our environment.  Converting energy into power.  A horse’s physiology can produce energy.  By feeding, watering and resting a horse we can convert that energy into power.  And with that power we can do greater work than we can do with our own physiology.  Working with horse-power has been the standard for millennia.  Especially for motive power.  Moving things.  Like dragging a plow.  But man has harnessed other energy.  Such as moving water.  Using a waterwheel.  Go into an old working cider mill in the fall and you’ll see how man made power from water by turning a wheel and a series of belts and pulleys.  The waterwheel turned a main shaft that ran the length of the work area.  On the shaft were pulleys.  Around these pulleys were belts that could be engaged to transfer power to a work station.  Where it would turn another pulley attached to a shaft.  Depending on the nature of the work task the rotational motion of the main shaft could be increased or decreased with gears.  We could change it from rotational to reciprocating motion.  We could even change the axis of rotation with another type of gearing.

This was a great step forward in advancing civilization.  But the waterwheel, shaft, pulleys and belts made power transmission complex.  And somewhat limited by the energy available in the moving water.  A great step forward was the steam engine.  A large external combustion engine.  Where an external firebox heated water to steam.  And then that steam pushed a piston in a cylinder.  The energy in expanding steam was far greater than in moving water.  It produced far more power.  And could do far more work.  We could do so much work with the steam engine that it kicked off the Industrial Revolution.

Nikola Tesla created an Electrical Revolution using AC Power

The steam engine also gave us more freedom.  We could now build a factory anywhere we wanted to.  And did.  We could do something else with it, too.  We could put it on tracks.  And use it to pull heavy loads across the country.  The steam locomotive interconnected the factories to the raw materials they consumed.  And to the cities that bought their finished goods.  At a rate no amount of teamed horses could equal.  Yes, the iron horse ended man’s special relationship with the horse.  Even on the farm.  Where steam engines powered our first tractors.  Giving man the ability to do more work than ever.  And grow more food than ever.  Creating greater food surpluses than the Sumerians and Egyptians could ever grow.  No matter how much of their fertile river banks they cultivated.  Or how much land they irrigated.

Steam engines were incredibly powerful.  But they were big.  And very complex.  They were ideal for the farm and the factory.  The steam locomotive and the steamship.  But one thing they were not good at was transmitting power over distances.  A limitation the waterwheel shared.  To transmit power from a steam engine required a complicated series of belts and pulleys.  Or multiple steam engines.  A great advance in technology changed all that.  Something Benjamin Franklin experimented with.  Something Thomas Edison did, too.  Even gave us one of the greatest inventions of all time that used this new technology.  The light bulb.  Powered by, of course, electricity.

Electricity.  That thing we can’t see, touch or smell.  And it moves mysteriously through wires and does work.  Edison did much to advance this technology.  Created electrical generators.  And lit our cities with his electric light bulb.  Electrical power lines crisscrossed our early cities.  And there were a lot of them.  Far more than we see today.  Why?  Because Edison’s power was direct current.  DC.  Which had some serious drawbacks when it came to power transmission.  For one it didn’t travel very far before losing much of its power. So electrical loads couldn’t be far from a generator.  And you needed a generator for each voltage you used.  That adds up to a lot of generators.  Great if you’re in the business of selling electrical generators.  Which Edison was.  But it made DC power costly.  And complex.  Which explained that maze of power lines crisscrossing our cities.  A set of wires for each voltage.  Something you didn’t need with alternating current.  AC.  And a young engineer working for George Westinghouse was about to give Thomas Edison a run for his money.  By creating an electrical revolution using that AC power.  And that’s just what Nikola Tesla did.

Transformers Stepped-up Voltages for Power Transmission and Stepped-down Voltages for Electrical Motors

An alternating current went back and forth through a wire.  It did not have to return to the electrical generator after leaving it.  Unlike a direct current ultimately had to.  Think of a reciprocating engine.  Like on a steam locomotive.  This back and forth motion doesn’t do anything but go back and forth.  Not very useful on a train.  But when we convert it to rotational motion, why, that’s a whole other story.  Because rotational motion on a train is very useful.  Just as AC current in transmission lines turned out to be very useful.

There are two electrical formulas that explain a lot of these developments.  First, electrical power (P) is equal to the voltage (V) multiplied by the current (I).  Expressed mathematically, P = V x I.  Second, current (I) is equal to the voltage (V) divided by the electrical resistance (R).  Mathematically, I = V/R.  That’s the math.  Here it is in words.  The greater the voltage and current the greater the power.  And the more work you can do.  However, we transmit current on copper wires.  And copper is expensive.  So to increase current we need to lower the resistance of that expensive copper wire.  But there’s only one way to do that.  By using very thick and expensive wires.  See where we’re going here?  Increasing current is a costly way to increase power.  Because of all that copper.  It’s just not economical.  So what about increasing voltage instead?  Turns out that’s very economical.  Because you can transmit great power with small currents if you step up the voltage.  And Nikola Tesla’s AC power allowed just that.  By using transformers.  Which, unfortunately for Edison, don’t work with DC power.

This is why Nikola Tesla’s AC power put Thomas Edison’s DC power out of business.  By stepping up voltages a power plant could send power long distances.  And then that high voltage could be stepped down to a variety of voltages and connected to factories (and homes).  Electric power could do one more very important thing.  It could power new electric motors.  And convert this AC power into rotational motion.  These electric motors came in all different sizes and voltages to suit the task at hand.  So instead of a waterwheel or a steam engine driving a main shaft through a factory we simply connected factories to the electric grid.  Then they used step-down transformers within the factory where needed for the various work tasks.  Connecting to electric motors on a variety of machines.  Where a worker could turn them on or off with the flick of a switch.  Without endangering him or herself by engaging or disengaging belts from a main drive shaft.  Instead the worker could spend all of his or her time on the task at hand.  Increasing productivity like never before.

Free Market Capitalism gave us Electric Power, the Electric Motor and the Roaring Twenties

What electric power and the electric motor did was reduce the size and complexity of energy conversion to useable power.  Steam engines were massive, complex and dangerous.  Exploding boilers killed many a worker.  And innocent bystander.  Electric power was simpler and safer to use.  And it was more efficient.  Horses were stronger than man.  But increasing horsepower required a lot of big horses that we also had to feed and care for.  Electric motors are smaller and don’t need to be fed.  Or be cleaned up after, for that matter.

Today a 40 pound electric motor can do the work of one 1,500 pound draft horse.  Electric power and the electric motor allow us to do work no amount of teamed horses can do.  And it’s safer and simpler than using a steam engine.  Which is why the Roaring Twenties roared.  It was in the 1920s that this technology began to power American industry.  Giving us the power to control and shape our environment like never before.  Vaulting America to the number one economic power of the world.  Thanks to free market capitalism.  And a few great minds along the way.

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